Qt的DIY滚动条问题？

[中才德创]

#include <QWindowsStyle>

class newStyle : public QWindowsStyle
{
    Q_OBJECT

public:
	newStyle();
	virtual int pixelMetric(PixelMetric pm, const QStyleOption * opt=0, const QWidget * widget=0) const; //重载函数
	virtual void drawComplexControl(ComplexControl cc, const QStyleOptionComplex *opt, QPainter *p, const QWidget *widget=0) const; //重载函数

private:
	void diyScrollBar(const QStyleOptionComplex *opt, QPainter *p) const; //重画滚动条

private:
    QPixmap *m_pBkPixmap;
    QPixmap *m_pHndPixmap;
};

一般这种实现的思路来自哪的？网络上查找出来的吗？

[中才德创]

[Quote=引用 2 楼 的回复:]
滚动条自己画很费劲，还不如用Qss：http://developer.qt.nokia.com/doc/qt-4.8/stylesheet-examples.html
[/Quote]确实如此

void newStyle::diyScrollBar(const QStyleOptionComplex *opt, QPainter *p) const
{
    QRect scrollbarRect = opt->rect;
    p->save();
    p->setClipRect(scrollbarRect, Qt::IntersectClip);

    QRect rectSubCtrlGroove = subControlRect(CC_ScrollBar, opt, SC_ScrollBarGroove); //获取子控件的RECT
    QRect rectSubCtrlHandle = subControlRect(CC_ScrollBar, opt, SC_ScrollBarSlider); //获取子控件的RECT

    QRect rectAddLine = subControlRect(CC_ScrollBar, opt, SC_ScrollBarAddLine);
    QRect rectSubLine = subControlRect(CC_ScrollBar, opt, SC_ScrollBarSubLine);
    QRect rectAddPage = subControlRect(CC_ScrollBar, opt, SC_ScrollBarAddPage);
    QRect rectSubPage = subControlRect(CC_ScrollBar, opt, SC_ScrollBarSubPage);

    if (scrollbarRect.width() < scrollbarRect.height()) //垂直滚动条
    {
        //画按钮部分
        QRect rectDownPix(0, m_pBkPixmap->height()-13, 13, 13);
        p->drawPixmap(rectAddLine, *m_pBkPixmap, rectDownPix);
        p->drawPixmap(rectSubLine, *m_pBkPixmap, rectSubLine);

        //画底色部分
        QRect rectBodyPix(0, 13, 13, m_pBkPixmap->height()-26);
        p->drawPixmap(rectSubCtrlGroove, *m_pBkPixmap, rectBodyPix);

        //画滑块部分
        QRect rectHandleA(0, 0, 13, 5);
        QRect rectHandleCenter(0, 5, 13, 90);
        QRect rectHandleB(0, 95, 13, 5);

        QRect rectToDrawBegin(0, rectSubCtrlHandle.top(), 13, 5);
        QRect rectToDrawCenter(0, rectSubCtrlHandle.top()+5, 13, rectSubCtrlHandle.height()-10);
        QRect rectToDrawEnd(0, rectSubCtrlHandle.bottom()-5, 13, 5);

        if (m_pHndPixmap)
        {
            p->drawPixmap(rectToDrawBegin, *m_pHndPixmap, rectHandleA);
            p->drawPixmap(rectToDrawCenter, *m_pHndPixmap, rectHandleCenter);
            p->drawPixmap(rectToDrawEnd, *m_pHndPixmap, rectHandleB);
        }
    }
    else //水平滚动条
    {
        //将图片翻转一下
        QMatrix matrix;
        matrix.rotate(-90.0);
        QPixmap hBkPixmap;
        QPixmap hHndPixmap;

        hBkPixmap = m_pBkPixmap->transformed(matrix);
        hHndPixmap = m_pHndPixmap->transformed(matrix);

        //画按钮部分
        QRect rectToDrawDown(hBkPixmap.width()-13, 0, 13, 13);
        p->drawPixmap(rectAddLine, hBkPixmap, rectToDrawDown);
        p->drawPixmap(rectSubLine, hBkPixmap, rectSubLine);

        //画底色部分
        QRect rectBodyPix(13, 0, hBkPixmap.width()-26, 13);
        p->drawPixmap(rectSubCtrlGroove, hBkPixmap, rectBodyPix);

        //画滑块部分
        QRect rectHandleA(0, 0, 5, 13);
        QRect rectHandleCenter(5, 0, 90, 13);
        QRect rectHandleB(95, 0, 5, 13);

        QRect rectToDrawBegin(rectSubCtrlHandle.left(), 0, 5, 13);
        QRect rectToDrawCenter(rectSubCtrlHandle.left()+5, 0, rectSubCtrlHandle.width()-10, 13);
        QRect rectToDrawEnd(rectSubCtrlHandle.right()-5, 0, 5, 13);

        if (m_pHndPixmap)
        {
            p->drawPixmap(rectToDrawBegin, hHndPixmap, rectHandleA);
            p->drawPixmap(rectToDrawCenter, hHndPixmap, rectHandleCenter);
            p->drawPixmap(rectToDrawEnd, hHndPixmap, rectHandleB);
        }
    }

    p->restore();
}

[中才德创]

if (CC_ScrollBar == cc)若用switch代替，功能居然失效了？这又是为何？

#include <QtGui>
#include "newstyle.h"

/*
* 函数介绍：构造函数
			图片变量赋值
* 输入参数：无
* 输出参数：无
* 返回值  ：无
*/
newStyle::newStyle()
	: m_pBkPixmap(NULL), m_pHndPixmap(NULL)
{
    m_pBkPixmap = new QPixmap("./skin/scrollbar_background.png"); //滚动条背景
    m_pHndPixmap = new QPixmap("./skin/scrollbar_handle.png"); //滚动条滑块
}

/*
* 函数介绍：像素公制
* 输入参数：pm，像素公制；opt，选项；widget，控件
* 输出参数：无
* 返回值  ：调整值
*/
int newStyle::pixelMetric(PixelMetric pm, const QStyleOption * opt, const QWidget * widget) const
{
    switch (pm)
	{
    case PM_ScrollBarExtent: //宽
        return 13;

    case PM_ScrollBarSliderMin: //最小高
        return 15;

    default:
        return QWindowsStyle::pixelMetric(pm, opt, widget);
    }
}

/*
* 函数介绍：画复杂控件
* 输入参数：cc，复杂控件；opt，选项；p，画具；widget，控件
* 输出参数：无
* 返回值  ：调整值
*/
void newStyle::drawComplexControl(ComplexControl cc, const QStyleOptionComplex *opt, QPainter *p, const QWidget *widget) const
{
	if (CC_ScrollBar == cc)
	{
		diyScrollBar(opt, p);
	}
	else
	{
		return QWindowsStyle::drawComplexControl(cc, opt, p, widget);
	}
}

[jdwx]

滚动条自己画很费劲，还不如用Qss：http://developer.qt.nokia.com/doc/qt-4.8/stylesheet-examples.html